1. Field of the Invention
The present invention relates to a control device for controlling a machine tool, such as a machining center, etc.
2. Description of the Related Art
A device for reducing power consumption during machining of a workpiece is wellknown. The device described in Japanese Unexamined Patent Publication (kokai) No. 6-161535 (JP6-161535A) is configured to extend acceleration time of an axis-feed servomotor so as to reduce a maximum value of required current, and thus reduces power consumption.
In such a machine tool, not only the axis-feed motor but also equipment which operate at a constant power, such as an oil pump for supplying cutting oil, etc., is driven at the same time during machining of a workpiece. Therefore, in the device described in JP6-161535A, in which acceleration time of the servomotor is extended, it is difficult to optimally reduce total power consumption expended by the machine tool, because the cycle time increases, and thereby the power consumption of the above mentioned equipment increases.